| 0.25×3.2×125 | 28×0.25+28×![]() | 6.28- - +3.72 | (0.125+ + )×24. |
=0.25×0.4×8×125,
=(0.25×0.4)×(8×125),
=0.1×1000,
=100;
(2)28×0.25+28×
,=28×(0.25+
),=28×1,
=28;
(3)6.28-
-
+3.72,=6.28+3.72-
-
,=(6.28+3.72)-(
+
),=10-1,
=9.
(4)(0.125+
+
)×24,=0.125×24+
×24+
×24,=3+18+10,
=31.
分析:(1)把3.2分成0.4×8,再根据乘法结合律进行计算.
(2)根据乘法分配律进行计算,
(3)先加法交换律和减法的性质进行计算,
(4)根据乘法分配律进行计算.
点评:本题主要考查了学生在四则运算中灵活运用简便算法的计算能力,注意要认真细心.